Abrading device



Nov. 19, 1929.

E. C. SCHACHT ABRADING DEVICE Filed June 2.5. 1927 2 Sheets-Sheet l Nov. 19, 1929. E. c. scHAcHT ABRADING DEVICE Filed June 25,'1927 2 sheets-sheet 2 lll LLLL Patented Nov. 19, 1929 PATENT OFFICE ELMER C. SCHACHT, 0F TROY, NEW YORK,

TION, OF TROY, NEW YORK, A

ASSIGNOR T0 BEHR-MANNING COB/PCBA.- CORPORATION OF NEW YORK `ABRADIN' G DEVICE application mea .Tune 25,

The present invention relates to abrading .devices and more especially to improved means for attaching and securing an abrasive element to a Irevoluble supporting disc or the like. L

An important feature ofthe invention is the provision of a rotatable supportin member with attaching wings adapted to'enter slots oropenings directed outwardly from the center of an abrasive disc, the free edges of the wings and the edges of the slots being angularly related, so that the wings gradually enter the slots of the disc upon relative rotation of the wings and disc. Carrying out this idea, the invention contemplates the provision of radially disposed slits or openings .in the sanding disc cooperating with the free edges of the wings which are directed along lines at an angle to the radii of the supporting disc and sanding disc.

A further feature of the invention consists in providing an abrasiveelement or disc with a centrally disposed opening having cuts or slits extending towards-the outer edge of the disc, one edge of each of the cuts being depressed or defiected to extend substantially parallel to the other edge and provide an opening of uniform width throughout a substantial portion of its length. The abrasive surface of each deiected edge of the slits has preferably a relatively smooth portion to facilitate the entry of the attaching instruentalities carried by the supportingmem- Another feature of the invention is to provide a simple, inexpensive and eicient means f for positively securing an abrasive element to a supporting disc, and which permits the abrasive element to be readily attached or removed from engagement with the supporting disc. Additlonally, the parts are constructed' so as to be easily assembled or disassembled for the purpose of replacing such of them as has become defective or worn out through usage. y

v Other objects and features of the inventionv ,will become apparent from'the following description when taken in conjunctionwith the accompanying claims.

Referring to the drawing in which is dis- 1927. serial" No. 201,437.

closed a preferred embodiment of the veloplnentd Figure 1 is a side elevation of an abrading machine with the invention ap lied thereto.

Figure 2 is a front view of igure 1.

Figure 3 is a sectional view taken substantially alongthe line 3 -3 of Figure 2.

Figure l4 is an enlarged front View of the supporting disc that carries the abrasive element. l

Figure 5 is a fragmentary enlarged front view showing the initial position of the abrading element relative to the supporting disc.

Figure 6 is a sectional view taken substantially along the .line 6-6 of Figure 2.

Figure 7 is a sectional view taken substantially along the line 7 -7 of Figure 3.

Figure 8 is a sectional view of a portion of the disc taken along a line extending transversely of one of the radial slits, as illustratedby'the line 8 8 of Figure 9.

Figure 9 is a sectional view of a portion of the disc along a line diametrical of the central opening and lon 'tudinally of the radial slits, as illustrated y the line 9-9 of Fi ure 8.

eferring tothe drawing, in which like numerals indicate like parts in the various views, 10 denotes the casing of an'abrasive machine which is provided with a drive shaft 11l that may be actuated by any suitable drive mechanism, not shown. A The shaft 11 terminates in a reduced threaded end 12 to which is secured the collar 14, which collar has a projecting stud 13 and an annular flange 15 surrounding the adjacent periphery of the shaft 11. A washer 16 may be interposed between the opposed faces of the collar 14 and the shaft 11.

A series of backing plate 17, 18 and 19 of progressively increasing diameters are preferably associated with the collar 14,and act as a support for a body 20, preferably of yieldable material, such as felt. This mal terial may be secured to the backing 19 in any suitable manner, as by rivets 21, one of which is shown in Figure 6'.

The stud 13 of the collar 14, has an exter- 2A Ml j complementary portion 23 `of a sleeve 24,

which sleeve is preferably integral with carrying means, such as the supporting disc V14 b -the rivets 26 (Fig. 6).

25, for attaching wings 28 and 29. The back supporting members 17, 18 and 19, and the disc 25 are preferably secured to the collar e outer face o f the disc 25 is provided with a centerin hub 27 and, outwardly from 'the hub, attaclung wings or blades 28 and 29 (Fig. 4). Each of thse wings is preferably struck out or stamped from the disc 25, and

\ has a free straight edge 30 which is formed ata one end into a point 31 which, due to the disposition of the edge in other than a radial line, (in the present instance tangential to the hub) is disposed forwardly br in advance ofthe remainder of the edge. The edge 30 and point 31 are feathered or thinned (Fig.

7) so as to facilitate the entry .of the wingsI in an abrasive element 32. The points 31 are also curled upwardly (Fig. 3) to facilitate entrance of the same into the openings inthe sanding disc. It will be observed that the edges are oifset relative to each other around` the hub and extend along lines other vthan radial to the periphery of the hub 27,

so that upon relative turning of the wings and an abrasive disc, the points of the wings will first enter radial openings or slits in the abrasive disc.-

The abrasive velement 32 is preferably in the form of a sheet or disc, and may assume any suitable configuration as may be found desirable'or expedient. By the term disc as used in the specification, is 'meant any abrasive element, irrespective' of its form. The abrasive disc 32 has a central opening 33 of slightly larger diameter than the hub 27, arrangedto receive the hub when the disc is mounted on the rotatable head. Extending 4radially toward the disc margin, and in the present instance communicating with the central opening 33 of the abrasive disc, are the cuts, slits, or openings 34 and 35 (Fig. 5)

which are disposed on substantially diametrically oppositesides of the hub 27, and are arranged to receive the wings 28 and 29 ofthe supporting disc 25. As will be understood, the relative disposition of the free edges 30 onthe wings andthe complemental slits o r openings in the sanding disc cause the edges of the wings gradually to enter the slits as the sandingdisc and wings are relatively rotated. In other words, the entering edges of surface of one edgeof each of these cuts is de# pressed or deflected downwardly as at 36 v(Fig..j'8), and the. abrasive surface smoothed or removed therefrom so as to provide a relatively lplane portion 37. l

of the openings or slits 34, 35 has4 its deflected edge 36 so disposed that its edge ex-r,A tends substantially parallel to non-deflected ping the rotation of the drive shaft 1'1 and s applying the abrasive element 32 so that the slits 34 and 35 willregister wit-h the pointed ends of the wings. 28 and 2 9 respectively. The abrasive disc 32 is then revolved in the direction shown by the arrow in Figure'5, until the wings 28 and 29 have passed completely through the slits 34 and 35 and-the parts are in the position shown in Figure 2, n

when' the abrasive element will then be firmly secured in position. Conversely, when it is desired to remove the abrasive element from A the supporting disc 25. this may be readily effected by rotating the abrasive element on the `disc in a counter-clockwise direction.

The supporting head or body 20 has a central opening 20 in which is positioned the disc 25 so that when the parts are assembled, as shown in Figures 3 and 6, the disc 25 and the wings 28 and 29 will bebelow the plane of the operative portion of the abrasive surface which is disposed radially outwardly from the wings. s

4.This depressed arrangement of the disc and wings does not make it inconvenient to attach the abrasive element due to the fact that the latter is formed with the downwardf ly deflected edges 36,' which readily iit beneath the wings upon relative rotation of the abrasive disc and wings, notwithstanding the fact that the wings are below the plane of the remainder' of the disc. The depressed position of the wings is desirable to avoid contact ofthe same with thev object to which the abrasive element is applied.

As the machine may be readily assembled or disassembled. and .since the essential elements thereof can be separately manufactured, it will be seen that should any of the parts need to be replaced, the same may be economically 'effected .without requiring, the l renewal of the other parts. Moreover, due to the particular attaching means employed, abrasive elements of various kinds and types can be used with the machine, depending upon the work to be done. Y It is to be understood that the form of the invention herewith shown and described is merely illustrative of a preferred embodiment ofthe development, and that such changes as fall within the purview of one skilled in the art may be made without `de parting from the spirit of the invention and the scope of the appended claims.

What I claim is:

l. A substantially flexible abrasive element of the class described, having a central opening and openings disposed outwardly of the central opening, one edge of each of the outwardl disposed openings being depressed and tlile abrasive surface adjacent the same being relatively smooth.

2. An abrasive element of the class described, comprising a substantially yieldable disc having a central opening and an opening disposed outwardly therefrom, the outwardly disposed opening having one edge depressed and the abrasive surface adjacent the same being relatively smooth, said depression being such as to provide an opening of uniform width throughout a substantial portion of the length thereof.

3. A disc of the class described having an abrasive surface, said disc being formed with a` central opening and outwardly extending openings on substantially opposite sides of the central opening, one edge of the abrasive surface adjacent each of the outwardly1 extending openings having a depressed relatively smooth portion.

4. A disc of the class described having an abrasive surface, said disc being formed with a central opening and slits disposed outwardly of the central opening and communicating therewith, one edge of the abrasive surface adjacent each of the slits being depressed a uniformdistance through a substantial portion of the slit whereby'to form an opening of uniform width.

5. As anew article of manufacture, a disc having an abrasive surface and a substantially central opening, said disc being cut in a direction towards the outer edge of the disc from said opening, one edge of said cut being deflected from the plane ofI the other edge and having a substantial portion thereof paralleling said other edge whereby to provide an opening between said edges of substantially uniform width.

6. As a new article of manufacture, a disc having an abrasive surface and a substantially central opening, said disc being cut in a direction towards the outer edge of the disc from said opening, one edge of said cut being deflected from the plane of its other edge and having a substantial portion thereof paralleling said other edge whereby to rovide an opening between said 'edges of su vstantiall-y uniform width, the ldeflected edge being relatively smooth.

7. A device of theclass described comprising a revoluble supporting disc having a centering vhub and wings located outwardly thereof, each of said wings having a free edge forming at one end with an adjacent edge a point disposed forwardly of the remainder of the edge in a direction circumferentially of the disc. j

8. A device of the class described comprising a revoluble supporting disc having a centering hub and wings located outwardly thereof, each of said wings having a free, substantially straight edge forming at one end with an adjacent edge a point disposed forwardly of the remainder of the edge Ain a direction circumferentially ofthe disc.

9. A device'of the class described comprising a revoluble supporting dischaving a centering hub and wings located outwardly thereof, each of saidwings having a free edge forming with an adjacent edge at one end a point disposed forwardly of the remainder of the edge, said edge being disposed lat an angle .to the radii of said disc.

vhaving a. free edge formed with an adjacent edge into a point adapted to enter initially into a complemental opening in an abrasive disc, and an abrasive disc having a hub receiving opening and an opening complemental to each wing, said wing free edge and said complemental openings, when said disc and support are assembled, one extending substan-` tially radially with respect to said hub and the other atan angle thereto whereby to cause gradual entry of the ends of the wings into said openings upon relative rotation of the wings and disc.

sov

12. In a device of the class described, a

revoluble support having a centering hub and wings outwardly thereof, each having a free edge formed with an adjacent edge at the I inner end of the free edge intoa'point adapted to enter initially into a complemental opening in an abrasive disc, and an abrasive disc having a hub receiving opening and an opening complemental to each wing, said wing free edge and said complemental disc openings,

when said disc and support are assembled,

one extending substantially radially with. re-

spect to said-hub and the other at an angle,

thereto whereby to cause gradual entry of the ends of thawings into said openings upon relative rotation of the wings and disc.

13. In a device of the class described, a revoluble support having a centering hub and wings outwardly thereof, each wing having a free edge formed with an adjacent edge into a point, said point being disposed in advance of the remainder of said edge around the hub and the edge being directed at an angle to 'a radial line extending from the hub, and an abrasive disc having an opening to receive said hub and substantially radially extending openings each complemental to one of said wings whereby to gradually receive` the edges of said wings upon relative rotation of the wings and discs.

14. In a device of the class described, a revoluble support having a centering hub and wings outwardly thereof, each wing having a substantially straight free edge formed at its inner end into a point, said point being disposed in advance of the remainder of said edge around the hub andthe edge being directed at an angle to a radial line extending from the hub, and an abrasive disc having an opening to receive'said hub and substantially radially extending vopenings each complemental to one of said wings whereby to gradually receive the edges of said Wings upon relative rotation of the Wings and disc.`

15. An abrasive disc having a central opening yand slits extending outwardly therefrom, one edge of certain of said slits being depressed but having a substantiall part of the depressed portion maintained in parallelism with the other edge. I

16. An abrasive disc having a central opening and slits extending outwardly therefrom, one edge of certain of said slits having the abrasive surface adjacent the saine relatively smoothed.

In testimony whereof I have hereunto set my hand.

' ELMER C. SCHACHT. 

